Simplify the following expression: $n = \dfrac{8x}{5} - \dfrac{x}{4}$
In order to subtract expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $5$ and $4$ $\lcm(5, 4) = 20$ $ n = \dfrac{4}{4} \cdot \dfrac{8x}{5} - \dfrac{5}{5} \cdot \dfrac{x}{4} $ $n = \dfrac{32x}{20} - \dfrac{5x}{20}$ $n = \dfrac{32x -5x}{20}$ $n = \dfrac{27x}{20}$